Non-adiabatic transitions in the density matrix formalism

Abstract:We show that a density matrix formalism provides a useful description of non-adiabatic transitions in two-state quantum systems. Compared to a traditional Hamiltonian formalism, even in the absence of decoherence when there is full equivalence between the two, the density matrix formalism provides a convenient change of variables that yields a powerful general analytical solution. This solution nicely describes a transition regime between the well known Landau-Zener-Stuckelberg-Majorana (LZSM) approximation and the extremely non-adiabatic limit. Our results have very general applications, within a large variety of problems in quantum physics, neutrino physics, cosmology.

27 pages, 3 figures; v2: ref.'s added, appendix expanded

arXiv:2606.24310 [quant-ph]

(or arXiv:2606.24310v2 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2606.24310 Focus to learn more arXiv-issued DOI via DataCite

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